US 20050283358 A1
An apparatus and method for providing visual indication of character ambiguity and ensuing reduction of such ambiguity during text entry are described. An application text entry field is presented in a display screen, into which the user enters text by means of a reduced keyboard and a disambiguating system. The default or most likely word construct for the current key sequence may be presented at the insertion point of the text entry field. An indication of ambiguity is presented in the display screen to communicate to the user the possible ambiguous characters associated with each key. A word choice list field may also be present to display at least one word construct matching the current key sequence.
1. A method, comprising the steps of:
in response to pressing of one or more keys by a user, where at least one key corresponds to a plurality of characters, presenting an ambiguity field in a display screen to facilitate display of at least one character corresponding to each of said one or more keys; and
facilitating display of at least one candidate word construct matching a sequence of said one or more keys.
2. The method according to
facilitating display in highlighted form of a candidate character of said at least one character corresponding to each of said one or more keys, said candidate character being part of a selected candidate word construct.
3. The method of
facilitating removal or deemphasis of one or more characters of said at least one character corresponding to each of said one or more keys, said one or more characters being removed or deemphasized as not part of a candidate word construct.
4. The method of
in response to a user selecting a character of said at least one character corresponding to each of said one or more keys, facilitating display of only candidate word constructs matching said selected character in the corresponding position of the key sequence of each word construct.
5. An apparatus, comprising:
means for presenting a text entry field in a display screen to facilitate display of a selected word construct, in response to successive selection of one or more keys, each key corresponding to at least one character;
means for presenting an ambiguity field in said display screen to facilitate display of at least one character for said each key; and
means for facilitating display of at least one word construct formed by combining said at least one character for said each key, said at least one word construct including said selected word construct.
6. The apparatus according to
means for facilitating display in highlighted form of a candidate character of said at least one character for said each key, said candidate character being selected as part of said selected word construct.
7. The apparatus according to
means for facilitating display in highlighted form of a candidate word construct of said at least one word construct, said candidate word construct being selected as most likely to represent a word desired by said user.
8. The apparatus according to
means for facilitating removal or deemphasis of characters of said at least one character corresponding to said each key, said characters being removed or deemphasized as not part of a candidate word construct.
9. A machine-readable medium containing executable instructions, which, when executed in a processing system, cause said processing system to perform a method comprising the steps of:
in response to processing of a plurality of keys by said user, where each key corresponds to at least one character forming at least one word construct, presenting an ambiguity field in a display screen to facilitate display of said at least one character for said each key; and
facilitating display in highlighted form of a candidate word construct of said at least one word construct, said candidate word construct being selected as most likely to represent a word construct desired by said user.
10. The machine-readable medium according to
facilitating display in highlighted form of a candidate character of said at least one character corresponding to said each key, said candidate character being selected as part of said candidate word construct.
11. The machine-readable medium according to
facilitating removal or dimming of characters of said at least one character corresponding to said each key which are not part of a candidate word construct.
12. A method, comprising the steps of:
to select a symbol in response to a user input, where said user input is ambiguous with regard to an intended symbol presenting an ambiguity field in a display screen to display at least one symbol, that potentially corresponds to said user's intended input symbol; and
facilitating display in highlighted form of a candidate symbol sequence.
13. The method according to
facilitating display in highlighted form of a candidate symbol of said at least one symbol corresponding to said intended symbol, said candidate symbol being part of a selected candidate symbol sequence.
14. The method of
facilitating the removal or deemphasis of one or more symbols of said at least one symbol corresponding to said intended symbol, said one or more symbols being removed or deemphasized as not part of a candidate symbol sequence.
15. The method of
in response to a user selecting a symbol, facilitating display of only candidate symbol sequences matching said selected symbol in a corresponding position in said symbol sequence.
This application is a Continuation-in-Part of co-pending application, U.S. Ser. No. 10/176,933, filed on Jun. 20, 2002, and entitled EXPLICIT CHARACTER FILTERING OF AMBIGUOUS TEXT ENTRY (Attorney Docket No. TEGI0002). This co-pending application is incorporated herein in its entirety by this reference thereto. This application also claims priority from U.S. Provisional Patent Application Ser. No. 60/625,378, filed on Nov. 5, 2004, and entitled VISUAL INDICATION OF CHARACTER AMBIGUITY AND THE ENSUING REDUCTION OF AMBIGUITY DURING (T9) TEXT ENTRY, which is also incorporated herein in its entirety by this reference thereto.
1. Technical Field
The invention relates to text input technology. More specifically, the invention relates to text entry solutions to wireless communication devices which have limited keypads.
2. Description of the Prior Art
For many years, portable computers have been getting smaller and smaller. The principal size-limiting component in the effort to produce a smaller portable computer has been the keyboard. If standard typewriter-size keys are used, the portable computer must be at least as large as the keyboard. Miniature keyboards have been used on portable computers, but the miniature keyboard keys have been found to be too small to be easily or quickly manipulated by a user. Incorporating a full-size keyboard in a portable computer also hinders true portable use of the computer. Most portable computers cannot be operated without placing the computer on a flat work surface to allow the user to type with both hands. A user cannot easily use a portable computer while standing or moving.
Presently, a tremendous growth in the wireless industry has spawned reliable, convenient, and very popular mobile devices available to the average consumer, such as cell phones, PDAs, MP3 players, etc. Handheld wireless communications and computing devices requiring text input are becoming smaller still. Further, advances in portable wireless technologies have led to a demand for small and portable two-way messaging systems, both SMS and e-mail, and for mobile Web browsing. Wireless communications device manufacturers also desire to provide devices which the consumer can operate with the same hand that is holding the device.
Prior development work has considered use of a keyboard that has a reduced number of keys. As suggested by the keypad layout of a touch-tone telephone, many of the reduced keyboards have used a 3-by-4 array of keys. Each key in the array of keys contains multiple characters. There is therefore ambiguity as a user enters a sequence of keys, because each keystroke may indicate one of several letters. Several approaches have been suggested for resolving the ambiguity of the keystroke sequence, referred to as disambiguation.
One suggested approach for unambiguously specifying characters entered on a reduced keyboard requires the user to enter, on average, two or more keystrokes to specify each letter. The keystrokes may be entered either simultaneously (chording) or in sequence (multiple-stroke specification). Neither chording nor multiple-stroke specification has produced a keyboard having adequate simplicity and efficiency of use. Multiple-stroke specification is inefficient, and chording is complicated to learn and use.
Other suggested approaches for determining the correct character sequence that corresponds to an ambiguous keystroke sequence are summarized in Arnott, Probabilistic Character Disambiguation for Reduced Keyboards Using Small Text Samples, Journal of the International Society for Augmentative and Alternative Communication Arnott and M. Y. Javad (hereinafter the Arnott article). The Arnott article notes that the majority of disambiguation approaches employ known statistics of character sequences in the relevant language to resolve character ambiguity in a given context. The article also references research on word-based disambiguation systems and their respective advantages and disadvantages.
T9ฎ Text Input is the leading commercial product offering word-level disambiguation for reduced keyboards, as taught in U.S. Pat. No. 5,818,437 and subsequent patents. Ordering the ambiguous words by frequency of use reduces the efficiency problems identified by previous research, and the ability to add new words makes it even easier to use over time. Input sequences may be interpreted simultaneously as words, word stems, and/or completions, numbers, and unambiguous character strings based on stylus tap location or keying patterns, such as multi-tap.
Another commonly used keyboard for small devices consists of a touch-sensitive panel on which some type of keyboard overlay has been printed, or a touch-sensitive screen with a keyboard overlay displayed. Depending on the size and nature of the specific keyboard, either a finger or a stylus can be used to interact with the panel or display screen in the area associated with the key or letter that the user intends to activate. Due to the reduced size of many portable devices, a stylus is often used to attain sufficient accuracy in activating each intended key.
The system described in U.S. Pat. No. 6,801,190 uses word-level auto-correction to resolve the accuracy problem and permit rapid entry on small keyboards. Because tap locations are presumed to be inaccurate, there is some ambiguity as to what the user intended to type. The user is presented with one or more interpretations of each keystroke sequence corresponding to a word, such that the user can easily select the desired interpretation. This approach enables the system to use the information contained in the entire sequence of keystrokes to resolve what the user's intention was for each character of the sequence.
Handwriting recognition is another approach that has been taken to solve the text input problem on small devices that have a touch-sensitive screen or pad that detects motion of a finger or stylus. Writing on the touch-sensitive panel or display screen generates a stream of data input indicating the contact points. The handwriting recognition software analyzes the geometric characteristics of the stream of data input to determine each character or word. Due to differences in individual writing styles and the limitations of handwriting technology on mobile devices, however, recognition accuracy is less than perfect, resulting in character ambiguity even though current handwriting systems do not typically reveal that ambiguity to the user.
A Need for Improvements to Current Disambiguation Methodologies
A specific challenge facing word-based disambiguation is that of providing sufficient feedback to the user about the keystrokes being input, particularly for the novice or infrequent user who is unfamiliar with the reduced keyboard layout or the disambiguation system. With an ordinary typewriter or word processor, each keystroke represents a unique character which can be displayed to the user as soon as it is entered. But with word-level disambiguation, for example, this is often not possible, because each entry represents multiple characters, and any sequence of entries may match multiple words or word stems. The ambiguity may confuse the first-time user if the system displays characters that change as each key is pressed: the user does not know that the system offers the desired word at the end, and he may needlessly attempt to fix each character before proceeding. Ambiguity is especially a problem when, for example, the user makes a spelling or entry error and is not aware of such error until the complete sequence is entered and the desired result is not presented. Displaying word stems that match the partial sequence reduces this problem, by showing when the user is on the right track towards the desired word, but does not eliminate it entirely, especially if some stems are concealed due to display space constraints.
U.S. Pat. No. 5,818,437 describes a keystroke window (102) that displays keycap icons representing the ambiguous key sequence, which confirms that the user pressed the intended keys. But the display provides neither an explanation of how the words are being assembled from that key sequence nor feedback that the user is on the right track.
Moreover, some alphabets, such as Thai and Arabic, contain more letters than the alphabet for English, which leads to even greater ambiguity on a reduced number of keys. Efficient and confident input of these languages demands a mechanism for reducing the appearance of that ambiguity when needed.
An apparatus and method for providing visual indication of character ambiguity and ensuing reduction of such ambiguity during text entry are described. An application text entry field is presented in a display screen, into which the user enters text by means of a reduced keyboard and a disambiguating system. The default or most likely word construct for the current key sequence may be presented at the insertion point of the text entry field. An indication of ambiguity is presented in the display screen to communicate to the user the possible characters associated with each key. A word choice list field may also be present to display at least one word construct matching the current key sequence.
It should be appreciated and understood by one of ordinary skill in the art that the discussion herein applies to characters and sequences of characters, which, when combined make a linguistic object or part of an object. A typical example is a character in any language, such as a letter, digit, punctuation mark, or any other symbol from a language. A typical example of an object or part of an object is a word or part of a word. However, the discussion herein equally applies to elements of other alphabetic, ideographic, and phonetic systems such as Chinese zhuyin, Japanese kana, and Korean jamos. Also, it should be noted that the objects do not have to be linguistic, because the disambiguating system claimed herein can be used to look up icons, phone numbers, or inventory records, as long as a type of symbolic string representation is present. Therefore, it should be appreciated that use of terms, such as letter, word, word stem, and the like is not limited only to those applications, and they are used to facilitate ease of reading and understanding the discussion herein.
When text is entered using a disambiguating text input system, the display often changes with each keystroke such as, for example, initially showing all possible ambiguities and further showing the ongoing convergence to a less ambiguous or even non-ambiguous solution, as illustrated in
As illustrated in
For example, as shown in
Next, if the user depresses the 6 key, corresponding characters m, n, o are displayed horizontally in the field 702, following the previously displayed characters g, h, and i, and word choices formed as a result of the successive depression of the 4 and 6 keys are displayed in field 703 of the succession screen
In the alternate embodiment illustrated in
In the alternate embodiment illustrated in
In one embodiment, the word choice list field 1003 is a scrolling field, which facilitates selection of a most likely word choice and enables the user to scroll up or down through the word choice list. The ambiguity field is updated as the user scrolls through the word choice list, to reflect the sequence of characters in the highlighted word choice.
In alternate embodiments, the ambiguity field 1002 may be displayed within or layered above the application text entry field 1001, or without the word choice list field displayed, and may include the sequence of numerals associated with each key depressed by the user.
U.S. patent application Ser. No. 10/176,933, which application is incorporated herein its entirety by this reference thereto, relates to a method and apparatus for explicit character filtering in ambiguous text entry. The invention provides embodiments including various explicit character selection techniques, such as 2-key and long-pressing, and means for matching words in a database using various methodologies.
Because explicit entry of characters reduces the ambiguity of an ambiguous key sequence, the effect can be reflected in the ambiguity field as shown in
In the sequence illustrated in
In one embodiment of the invention, the user is able to interact directly with the ambiguity field and select the desired character from each set of ambiguous characters. For example, on a touch-screen displaying the embodiment in
This becomes another means of explicitly entering a character. The system may offer a means to switch to a temporary mode for this explicit character entry. Depending on the letter chosen and the ambiguity of the matching word choices, the remaining ambiguity may be reduced significantly. For example, if at the step of
In another embodiment, the system determines which keypress of the current sequence is the most ambiguous, which may be defined as which explicit entry would most reduce the number of word choices, or based on the weighted frequency of the words and stems beginning with the sequence. The highlighted candidate character, or the entire ambiguous set, is marked with a different color or font attribute. Alternatively, the system may present the most ambiguous set in a list from which the user may select, automatically or upon a user action. This helps the user learn and appreciate when it may be beneficial to use an explicit method during entry. In another embodiment, each set of ambiguous characters is color-graded to indicate the characters' relative ambiguities.
For instance, if the user enters the sequence corresponding to 466 and the matching words/stems are:
Then, if the user selects n, the list changes to:
When the user subsequently presses the 3 key, only:
In a further embodiment, the user may temporarily connect an external keyboard to the device, e.g. via a Bluetooth wireless connection, and type the specific letter for each of one or more selected ambiguous inputs or complete the current word using only unambiguous inputs. The system may switch to a temporary mode for explicit character entry automatically when an external keyboard is detected. The reduction in ambiguity from any such inputs would again be reflected in the ambiguity field.
Some languages and key layouts may assign more characters per key than the device can display for each keypress, so a modified presentation of the ambiguity field must be used. In one embodiment, the characters on each key are sorted, first by those which are valid and second by frequency of use, and a predetermined number of them are displayed. In another embodiment, the character class, vowel group, or diacritic marks are indicated generically so that each need not be shown separately. With the horizontal format in
In another embodiment of the invention the ambiguity is only partially reduced by explicit entry. For example, after the user presses the 3 key on a phone that supports multiple European languages the system may display the set of characters d, e, f, ้, ่, and ๋ in the ambiguity field. If, through a means as described above, the user explicitly enters an e but does not have the means or desire to specify the accent, the system reduces the ambiguous set displayed for that input to e, ้, ่, and ๋. The remaining ambiguity based on the matching word choices may still be reduced significantly, which is reflected in a reduction in ambiguity among the other inputs shown in the ambiguity field.
As further illustrated in
Although the invention is described herein with reference to the preferred embodiment, one skilled in the art will readily appreciate that other applications may be substituted for those set forth herein without departing from the spirit and scope of the present invention.
Accordingly, the invention should only be limited by the Claims included below.